1. Field of the Invention
The present invention relates to an electrical connector, and particularly to a backplane connector having printed substrates therein which electrically engage with corresponding conductive contacts of the backplane connector by solderless.
2. Description of the Related Art
Fleck Research, the worldwide leader in information technology and market intelligence, announced an article, entitled xe2x80x9cA View from the Backplanexe2x80x9d, on Jan. 07, 2002 at the website, http://www.fleckresearch.com/news/enxe2x80x9499-10-18.htm. This article introduced some backplane connectors, for example, Teradyne and Molex""s HDM (High Density Metric) family of 2.0 mm connectors, FCI""s (Berg) Metral HB connectors, FCI""s new HMHS (Hard Metric High Speed) connector and AMP""s Z-PACK HS3 connector. These connectors have common features of high-density, high-speed and strict demand for impedance and crosstalk control.
U.S. Pat. Nos. 6,171,115 and 6,267,604, both issued to Tyco Electronics Corporation, each disclose a backplane connector including a dielectric housing and a plurality of circuit boards held in the housing. The housing includes a front housing and an organizer engaging with the front housing. Each circuit board provides a plurality of conductive tracks extending from a mating interface thereof to a mounting edge thereof. The mating interface extends beyond the front housing to mate with a mating connector. The mounting edge is secured with conductive terminals by soldering before the mounting edge and the terminals are inserted in slots of the organizer. U.S. Pat. No. 6,083,047, issued to Berg Technology, Inc., discloses an alternate backplane connector including a connector body of dielectric material and a plurality of integrated PCB modules arranged parallel, side-by-side inserted to the connector body. Each PCB module includes a pair of substrates, a plurality of terminals soldered onto an inner surface of each substrate and an insulating spacer sandwiched between the inner surfaces of the substrates. U.S. Pat. No. 6,168,469, issued to Hon Hai Precision Ind. Co., Ltd. discloses a similar backplane connector that the contacts are soldered to printed circuit boards. These connectors have several disadvantages. First, it requires a step of soldering the contacts to the printed substrates by Surface Mounting Technology (SMT). The SMT requires expensive machine, thereby increasing the manufacturing cost of the connectors. Second, when the substrates, which are originally designed for signal transmission are required to be replaced by substrates for power transmission, the substrates together with the contacts must be discarded. This is not economy. Third, there is no means for guiding contacts of a mating connector to engage with the mating surface of the substrates. Therefore, there is a disadvantage that noble metal plated on contacting portions of the signal contacts may wear off due to their wiping action against the corners of the edge of the substrate.
U.S. Pat. Nos. 6,293,827 and 6,174,202, both issued to Teradyne Inc., 6,343,955, issued to Berg Technology Inc., and 6,299,484, issued to Framatome Connectors International (FCI), each disclose a backplane connector having a plurality of contacts stamped and formed from metal ribs. Each contact has a mating end for engaging with a contact of a mating connector and a mounting end for mounting to a mother board. These contacts are relatively long and manufactured costly.
U.S. Pat. No. 5,980,321, issued to Teradyne Inc., and 6,220,896, issued to Berg technology Inc., each disclose a backplane connector including a plate between every two rows of signal contacts. One of the disadvantages of these backplane connectors is that the grounding plate has no spring arm for reliably contacting a corresponding grounding element of a mating connector. So, disconnection may happen between the grounding plate of this backplane connector and the grounding element of the mating connector. Hence, an improved electrical connector is required to overcome the disadvantages of the prior art.
A first objective of the present invention is to provide an electrical connector having printed substrates therein moveably engage with corresponding conductive contacts thereof such that it is very convenient to replace some of the printed substrates with other devices.
A second objective of the present invention is to provide an electrical connector having means located in front of printed substrates thereof for guiding contacts of a mating connector to contact corresponding conductive elements on the printed substrates.
A third objective of the present invention is to provide an electrical connector assembly having an improved guiding means for guiding a male connector thereof to correctly mate with a female connector thereof.
A fourth objective of the present invention is to provide an electrical connector having a plurality of contacts that are secured to an insulative member thereof in a unique way.
To obtain the above objectives, an electrical connector assembly comprises a male connector mountable to a first printed circuit board, a female connector mountable to a second printed circuit board and a guiding means for guiding the male connector to mate with the female connector correctly. The male connector include first and second individual housing portions engageable with each other, a plurality of printed substrates held between the firs and the second housing portions and a plurality of signal contacts and a plurality of grounding terminals attached to the second housing portion in face-to-face relationship. Each printed substrate has a plurality of first conductive pads near a first edge thereof and a plurality of second conductive pads near a second edge thereof which is orthogonal with the first edge. The first housing portion provides a plurality of wedge-shaped lead-in bars in front of the printed substrates for guiding contacts of the female connector to contact corresponding first conductive pads of the substrates. The second edges of the substrates extend out of the first housing portion into the second housing portion to be removeably sandwiched between correspond signal contacts and corresponding grounding terminals.
The female connector includes a dielectric member having a plurality of elongate wafers and defining a channel between every two near wafers, a plurality of signal contacts and a plurality of grounding terminals received in the channels with each grounding terminal confronting several signal contacts. Each grounding terminal has four retention latches and eight contacting arms at one side thereof and five tail portions at an opposite side thereof. The contacting arms are sorted in four pairs and between each pair there is a retention latch. Each retention latch has a cap portion at a top end thereof attached to the dielectric member, thereby retaining the grounding terminals to the dielectric member. The contacting arms are configured to engage with grounding elements of the female connector while the tail portions are configured to electrically contact corresponding conductive pads on the second printed circuit board. In a preferred embodiment, the contacting arms of the grounding terminals are somewhat stronger than the contacting portions of the signal contacts, so, the printed substrates sandwiched by the contacting arms and the contacting portions are pushed by the contacting arms toward the contacting portions to secure the electrical connection between the contacting portions and the second conductive pads. Retention portions of the signal contacts each define a slot such that the retention portions may straddle upon corresponding protrusions on a bottom surface of the dielectric member.
The guiding means includes a pair of frames, which define a chamber between each frame and an outmost lead-in bar of the first housing portion, at opposite ends of the first housing portion and a pair of guiding posts at opposite ends of the dielectric member. The guiding posts are received in corresponding chambers before the first housing portion engages with the dielectric member for guiding the male connector to mate with the female connector. Each frame provides two guiding keys unsymmetrically located in an inner surface thereof and each guiding post defines two guiding cuts in accordance with the guiding keys. The male connector can only mate with the female connector when the guiding keys are accommodated by corresponding guiding cuts, thereby providing anti-blindmating function.
Other objects, advantages and novel features of the invention will become more apparent from the following detailed description of the present embodiment when taken in conjunction with the accompanying drawings.